Abstract
Terms in the vorticity equation are approximated numerically for each of a act of grid points, map times and pressure levels in the lower stratosphere during January-February 1957. The hypothesis is advanced that the vorticity budget of the middle- and high-latitude, wintertime, lower stratosphere, even during periods of stratospheric warming, represents in the first approximation a balance between the advection term and the divergence term. It is a consequence of this hypothesis and some other approximations that a function Q of the height and temperature fields (T−z function) is a linear function of the height z for any given map. Statistical studies of this deduction show that the linear correlation coefficient between Q and z for any given map is around −0.9.
